The answer is A. In a reverse fault, the hanging wall moves up and the footwall moves down.
It is called a reverse fault because the movement of is reverse of a normal fault. Compressional stress is what causes reverse faults. The hanging wall and the foot wall are pressed together and it causes the hanging wall to move upwards and the foot wall moves downwards. This is a type of dip-slip fault, which is a fault that occurs due to the vertical movement of the faults.
